Shifting element comprising at least three shift positions for shifting two gear ratios

Abstract

A shift element comprising at least three shift positions for shifting two gear transmission ratios in which in a first end position, which corresponds to a first shift position, the first gear transmission ratio is engaged and in a second end position, which corresponds to a second shift position, the second gear transmission ratio is engaged, while in the central position, which corresponds to a third shift position, both gear transmission ratios are engaged.

The invention claimed is: 
     
       1. A shift element comprising a common shift actuator and two shifting sleeve halves, the shift actuator and the two shifting sleeve halves being axially movable with respect to each other, the shift element being shiftable between at least three shift positions for shifting two transmission gears;
 first and second channels being formed by the shift actuator, the first and the second channels being axially fixed in relation to each other, the first channel receives a first shifting sleeve half and the second channel receives a second shifting sleeve half; 
 radially outer exterior teeth of a first transmission gear being engaged, in a first axial end-position of the shift element, by radially inner claw teeth of the first shifting sleeve half, and the first axial end position is a first shift position of the shift actuator; 
 radially outer exterior teeth of a second transmission gear being engaged, in a second axial end position of the shift element, by radially inner claw teeth of the second shifting sleeve half, and the second axial end position is a second shift position of the shift actuator; 
 both of the radially outer exterior teeth of the first and the second transmission gears being engaged, in a central position of the shift element, respectively, by the radially inner claw teeth of the first and the second shifting sleeve halves, and in the central position of the shift element, the radially inner claw teeth of the first and the second shifting sleeve halves engage a synchronizer element, and the central position of the shift element corresponds to a third shift position of the shift actuator; 
 in each of the first and the second axial end positions of the shift actuator, the shift actuator directly contacts only one of the first and the second shifting sleeve halves. 
 
     
     
       2. The shift element according to  claim 1 , wherein the shift element comprises a synchronizer device with clutch elements ( 2 ), synchronizer rings ( 3 ) and the synchronizer element ( 4 ), the shift actuator being axially slidable and having first and second carrier elements located at axially opposite ends thereof and a central carrier element axially located between the first and the second carrier elements, the first channel being axially defined by the first carrier element and the central carrier element, and the second channel being axially defined by the central carrier element and the second carrier element,
 first and second springs, the first spring and the first shifting sleeve half being received within the first channel axially between the central carrier element and the first carrier element such that the first spring biases the first shifting sleeve half toward the first carrier element, and the second spring and the second shifting sleeve half being received within the second channel axially between the central carrier element and the second carrier element such that the second spring biases the second shifting sleeve half toward the second carrier element, 
 in the central position of the shift element, the first and the second springs respectively bias the first and the second shifting sleeve halves such that the radially inner claw teeth of the first shifting sleeve half engages the radially outer exterior teeth of the first transmission gear, radially outer teeth of a first synchronizer ring and radially outer teeth of the synchronizer element and the radially inner claw teeth of the second shifting sleeve half engages the radially outer exterior teeth of the second transmission gear, radially outer teeth of a second synchronizer ring and the radially outer teeth of the synchronizer element, and 
 of the first axial end position, the second axial end position and the central position of the shift element, the first and the second shifting sleeve halves both abut the shift actuator only when the shift element is in the central position. 
 
     
     
       3. The shift element according to  claim 1 , further comprising,
 the shift actuator being shiftable to axial positions from the first axial end position to the second axial end position and axial positions therebetween; 
 each of the first and the second shifting sleeve halves ( 8 ,  9 ) is couplable with a respective one of the first and the second transmission gears ( 6 ,  7 ); 
 the first and the second shifting sleeve halves ( 8 ,  9 ) are separately axially movable with respect to one another, such that depending on the axial position and direction of movement of the shift actuator, only one of the first and the second shifting sleeve halves ( 8 ,  9 ) is axially moved by the shift actuator at a time; 
 in the first axial end-position of the shift element, only the first shifting sleeve half of the first and the second shifting sleeve halves abuts the shift actuator, and in the second axial end-position of the shift element, only the second shifting sleeve half of the first and the second shifting sleeve halves abuts the shift actuator, and in the central position of the shift element, both of the first and the second shifting sleeve halves abut the shift actuator, and the first and the second shifting sleeve halves ( 8 ,  9 ) are biased in axially opposite directions from each other by at least one elastic element located therebetween such that the inner claw teeth of the first and the second shifting sleeve halves ( 8 ,  9 ) engage with radially outer teeth of the synchronizer element, and radially outer claw teeth of clutch elements ( 2 ) of a respective one of the first and the second transmission gears ( 6 ,  7 ) which are associated with the first and the second shifting sleeve halves ( 8 ,  9 ). 
 
     
     
       4. The shift element according to  claim 3 , wherein the shift actuator comprises a shift actuator receptor ( 10 ) having a carrier element ( 11 ) for each of the first and the second shifting sleeve halves ( 8 ,  9 ), by which the transmission gear that is couplable with each of the respective shifting sleeve halves is disengaged, and decoupling and coupling of the first and the second shifting sleeve halves ( 8 ,  9 ), when the shift element ( 1 ) is shifted, is effected by communication between the shift actuator receptor ( 10 ) and the first and the second shifting sleeve halves such that,
 in the first axial end-position of the shift element, the radially inner claw teeth of the first shifting sleeve half engage the radially outer claw teeth of a first clutch element, radially outer teeth of a first synchronizer ring and the radially outer teeth of the synchronizer element, and the radially inner claw teeth of the second shifting sleeve half engage radially outer teeth of a second synchronizer ring and the radially outer teeth of the synchronizer element, and 
 in the second axial end-position of the shift element, the radially inner claw teeth of the first shifting sleeve half engage radially outer teeth of the first synchronizer ring and the radially outer teeth of the synchronizer element, and the radially inner claw teeth of the second shifting sleeve half engage the radially outer claw teeth of a second clutch element, radially outer teeth of a second synchronizer ring, and the radially outer teeth of the synchronizer element. 
 
     
     
       5. A shift element comprising a common shift actuator and first and second shifting sleeve halves, the shift actuator and the first and the second shifting sleeve halves being axially movable with respect to each other, the shift actuator being axially shiftable between a first axial end position and a second axial end position for shifting first and second transmission gears, the first axial end position being a position at which axial movement of the shift actuator in one direction is blocked and the second axial end position being a position at which axial movement of the shift actuator in an opposite direction is blocked;
 first and second channels being formed by the shift actuator, the first and the second channels being axially fixed in relation to each other, the first channel receives the first shifting sleeve half and the second channel receives the second shifting sleeve half; 
 in the first axial end position of the shift actuator, inner claw teeth of the first shifting sleeve half engage outer claw teeth of the first transmission gear and the first shifting sleeve half is spaced from the shift actuator and the second shifting sleeve half directly abuts the shift actuator and the inner claw teeth of the second shifting sleeve half are disengaged from outer claw teeth of the second transmission gear; 
 in the second axial end position of the shift actuator, inner claw teeth of the second shifting sleeve half engage outer claw teeth of the second transmission gear and the second shifting sleeve half is spaced from the shift actuator and the first shifting sleeve half directly abuts the shift actuator and the inner claw teeth of the first shifting sleeve half are disengaged from outer claw teeth of the first transmission gear; 
 in a third axial position of the shift actuator centrally between the first and the second axial end positions of the shift actuator, both of the first and the second shifting sleeve halves abut the shift actuator, the outer claw teeth of both of the first and the second transmission gears are engaged, respectively, by the inner claw teeth of the first and the second shifting sleeve halves, and the inner claw teeth of the first and the second shifting sleeve halves engage a synchronizer element. 
 
     
     
       6. A shift element comprising a common shift actuator and two shifting sleeve halves, the shift actuator and the two shifting sleeve halves being axially movable with respect to each other, the shift actuator being shiftable between at least three shift positions for shifting two transmission gears;
 first and second channels being formed by the shift actuator, the first and the second channels being axially fixed in relation to each other, the first channel receives a first shifting sleeve half and the second channel receives a second shifting sleeve half; 
 radially outer exterior teeth of a first transmission gear being engaged, in a first end-position of the shift actuator, by radially inner claw teeth of the first shifting sleeve half, and the first end position is a first shift position and is an axial position at which axial movement of the shift actuator in one direction is blocked; 
 radially outer exterior teeth of a second transmission gear being engaged, in a second end position of the shift actuator, by radially inner claw teeth of the second shifting sleeve half, and the second end position is a second shift position and is an axial position at which axial movement of the shift actuator in an opposite direction is blocked; and 
 both of the radially outer exterior teeth of the first and the second transmission gears being engaged, in a central position of the shift actuator, respectively, by the radially inner claw teeth of the first and the second shifting sleeve halves, and in the central position of the shift actuator, the radially inner claw teeth of the first and the second shifting sleeve halves engage a synchronizer element, and the central position corresponds to a third shift position, and 
 only one of the first and the second shifting sleeve halves abut the shift actuator when the shift actuator is in either the first or the second axial end positions.